This disclosure relates in general to a method and system for controlling a flow of a substance through a conduit. More specifically, but not by way of limitation, some embodiments of the present invention provide for controlling both the backflow and the flow rate of the substance in the conduit. In an embodiment of the present invention, the backflow and the flow rate of the substance are controlled without the use of sliding parts using a moveable element, membrane or the like. Counter force mechanisms, spring constant of the moveable element, elasticity of the moveable element or the like, in certain embodiments of the present invention, may provide for full forward and/or backward flow control.
Previously, flow rate control systems have generally involved piston type systems. These piston systems are in general either dumb systems that do not adapt to changes in the flow in the conduit or are cumbersome systems with complex controlling mechanisms. Additionally, the piston systems do not address issues regarding control of backflow, are susceptible to deterioration in operation due to wear, corrosion, adverse affects of solid particulates and/or the like and are not capable of accurately controlling low flow rates.